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Anti-hygroscopic surface modification method by coating ammonium nitrate with hexadecanol

A technology of surface modification and cetyl alcohol, which is applied in ammonium nitrate fertilizers, explosives, applications, etc., can solve the problems of not strict moisture absorption conditions, less dosage, and less harsh conditions, and achieve accurate coating agent content and cost , simple process, safe and convenient operation

Inactive Publication Date: 2018-01-19
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the anti-moisture absorption methods on the surface of ammonium nitrate particles mainly include the following: 1) physical coating, forming a layer of hydrophobic film on the surface of ammonium nitrate particles to reduce the surface water absorption capacity, but the content and coating of physical coating coating agent The thickness of the layer is difficult to control; 2) Encapsulation coating, which can improve the physical properties of the surface of the coated particles, but when the residual liquid of the coating layer volatilizes, many holes will be generated, resulting in poor coating effect; 3) Chemical coating, the polar functional groups in organic substances such as surfactants and coupling agents are adsorbed on the particle surface or chemically reacted to produce bonding, and its non-polar functional groups extend outward to reduce its surface water absorption capacity. The advantage is the dosage Less, strong combination
[0004] Document 1 (Ye Zhiwen. Surfactants improve the hygroscopicity of ammonium nitrate [J]. Fine Chemical Industry. 2001) ammonium nitrate is modified with surfactants, and the ammonium nitrate is modified at 25 ° C, 75% and 96% humidity respectively. The hygroscopicity of modified ammonium nitrate was measured, and it was found that the composite surfactant can effectively reduce the hygroscopicity of ammonium nitrate by about 30%. Moisture absorption rate drop is not obvious enough
Document 2 (Yin Penggang, Shi Weicang, et al. Discussion on the application of monolayer self-assembly technology in the application of ammonium nitrate to prevent moisture absorption. [J], Applied Chemistry, 2000, 17(2), 186-187) using octadecylamine It is a surfactant, using xylene as a solvent to adsorb and coat ammonium nitrate, and absorb moisture for 24 hours under the conditions of temperature 25°C and relative humidity 92%, and the relative moisture absorption rate is between 58.6% and 82.6%, but the coating layer is not clearly indicated quality score and the conditions are not harsh enough
[0005] In summary, the existing anti-moisture absorption method on the surface of ammonium nitrate particles can significantly reduce the moisture absorption rate of ammonium nitrate particles under certain conditions. Not uniform and harsh, imprecise mass fraction of coating layer and imperfect process of surfactant coating ammonium nitrate
The method of carrying out anti-moisture modification of ammonium nitrate with aliphatic hydrocarbon alcohol surfactant as coating agent has not been reported yet

Method used

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  • Anti-hygroscopic surface modification method by coating ammonium nitrate with hexadecanol
  • Anti-hygroscopic surface modification method by coating ammonium nitrate with hexadecanol
  • Anti-hygroscopic surface modification method by coating ammonium nitrate with hexadecanol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A method for modifying the anti-hygroscopic surface of ammonium nitrate coated with cetyl alcohol, comprising the steps of:

[0020] Step 1: Mix 15mL of cyclohexane and 15mL of chloroform into a 50mL four-neck flask, and plug the glass stopper at any time. Then add 2g of cetyl alcohol until it is completely dissolved, and add 6g of ammonium nitrate solid particles that have been pulverized, passed through a 70-mesh sieve and dried to a four-necked flask at 20°C and the relative humidity is lower than 42%.

[0021] Step 2: Stir the flask in a collector stirrer and set the temperature at 60°C. When the temperature rose to 60°C, the reaction was carried out at a constant temperature for 2 hours, and then the temperature was gradually lowered to 25°C for 5 hours.

[0022] Step 3: Use a sand core funnel to filter the sample. When the last drop of solvent drops, spread the coated ammonium nitrate on a glass dish, shake it, dry it for 2 minutes, and then place it in an oven f...

Embodiment 2

[0040] Ammonium nitrate was coated with surfactants such as myristyl alcohol, cetyl alcohol, stearyl alcohol, eicosanol, and behenyl alcohol, and the other coating conditions were the same as in Example 1. The moisture absorption rate of ammonium nitrate coated with various alcohol surfactants was measured, and the results are shown in Table 2. From Table 2, it can be seen that cetyl alcohol has the best coating effect.

[0041] Table 2 Alcohol surfactant coated ammonium nitrate moisture absorption test results

[0042]

Embodiment 3

[0044] The difference between this example and Example 1 is that the stirring temperature in the second step is respectively 55°C, 60°C and 65°C, and other preparation conditions are the same as in Example 1, and the ammonium nitrate modified under different stirring temperatures is measured. The moisture absorption rate, the results are shown in Table 3. It can be seen from the table that the coating effect is the best when the stirring temperature is 60 °C, and the moisture absorption rate of the modified ammonium nitrate decreases the most.

[0045] The influence of table 3 stirring temperature on moisture absorption rate

[0046]

[0047]

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Abstract

The invention discloses an anti-hygroscopic surface modification method by coating ammonium nitrate with hexadecanol. Hexadecanol is used as a surfactant, and is dissolved in a mixed solvent of cyclohexane and trichloromethane, and ammonium nitrate particles are added for adsorption coating. The moisture absorption rate of the ammonium nitrate particles coated with hexadecanol is measured under test conditions that the temperature is 35 DEG C, the relative humidity is 68.5% and the moisture absorption time is 24 hours, the reduction amplitude of the moisture absorption rate and the mass fraction of the coating layer are taken as indexes, the mass fraction of the coating layer is 1.5 % or below, and the reduction amplitude of the moisture absorption rate can reach 49%. The method notably reduces the content of the coating agent, effectively improves the moisture absorption rate of ammonium nitrate under the condition that the content of the coating agent is reduced, lays a foundation for the process of coating ammonium nitrate with surfactants, scale-up experiments and industrialization, and has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of anti-moisture absorption modification on the surface of energetic materials, and relates to a method for modifying the anti-moisture absorption surface of ammonium nitrate coated with cetyl alcohol. Background technique [0002] Ammonium nitrate (AN) can be used not only as an oxidant for industrial explosives and solid propellants, but also as an important agricultural fertilizer. Ammonium nitrate itself is extremely hygroscopic and caking. The explosion energy of ammonium nitrate after moisture absorption is significantly reduced, and even explosion failure occurs. The agglomerated ammonium nitrate fertilizer not only causes great inconvenience to storage, transportation and use, but also has a hidden danger of explosion during its use and crushing. These problems seriously restrict the application and development of ammonium nitrate. Therefore reducing the hygroscopicity of ammonium nitrate is the ke...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C05G3/00C05C1/02C06B31/28C06B21/00
Inventor 张跃军巴哈侯文斌
Owner NANJING UNIV OF SCI & TECH